Furnace.



EATENTED A1111. 9, 1907. W. MOGLAVE.

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APPLIGATION FILED 111111.16, 1905.

PATBNTBD APRgs, 1907.

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PURNAGB- APPLICATION FILEI MAR. 16, 1905.

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TH: Nonms PETERS zal, wAsHlNcroN, D. c.

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WILLIAM MCOLAVE, OF SORANTON, PENNSYLVANIA, ASSIGNOR TO MCOLAVE- iBROOKS COMPANY, A CORPORATION OFl PENNSYLVANIA.

FURNACE.

Specification of Letters Patent.

Patented April 9, 1907.

Application filed March 16, 1905. Serial No. 250,469.

To all wlw/'ri t lim/ y concern: l

Be it known that I, WILLIAM McOLAvF., a

'citizen of the United States, residing at Scranton, in the county ofLackawanna and State of Pennsylvania, have invented certain new anduseful Improvements in Furnaces; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enableothers skilled in the art to which it appertains to make anduse the same.

rl`his invention relates to improvements in furnaces, and has particularrelation to the structure of the furnace by which air in a heatedcondition may be delivered to -the products of combustion as they passfrom the fire-box and through the flame and smoke-flues of the furnacemechanism. f

The invention comprises certain novel constructions, combinations, andarrangements of parts, as will be hereinafter fully described y andclaimed. I

In the accompanying drawings, Figure 1 is a vertical centrallongitudinal sectionl through a steam-boiler furnace constructed inaccordance with the present invention, the boiler being shown inelevation. Fig. 2 is a view, partially in top plan and partially inhorizontal section, showing the air-conducting flues and chambers. Fig.3 is a detail perspective view of a bridge-wall-apertureforming block orbrick.

In consuming various kinds of fuel-coal in furnaces it is well knownthat large quantities of carbon are liberated, which escape before theycan be caught by a sufficient quantity of oxygen to produce combustion,and the escape of these particles of carbon forms the dense black smokewhich is so objectionable.

rPhe present invention is designed for introducing and properly heatingair and delivering it at such a point in the furnace with respect to theproducts of combustion that the escape of these liberated particles ofcarbon will be to a large degree prevented.

I am aware that heated air has been delivered. into thecombustion-chambers of furnaces or into they ash-pits thereof g but thestructure to be described and claimed in this application is such as toenable me to utilize heat units which have heretofore been lost and alsoso deliver the air thus heated into the column of flame which passesfrom the pies a similar position.

fire-box into the flue of a boiler-furnace that advantageous results maybe obtained in advance of that which has already been accomplished inthis line.

I have illustrated in the accompanying drawings the manner in which Iprefer to construct furnaces for carrying the principle of the inventioninto effect and will now describe my improveinents, reference to be hadto the said drawings.

I have found in practice that the best results are obtained byconstructing ther furnace in suoli a manner that air may bedelivered ina heated condition and either under a natural or forced draft into thestream column of flame and burning products of a furnace as they passout of the fire-box and over the bridge-wall into the name-flue insteadof delivering the air directly into the fire-box or into the ash-pit.

Although the invention is ap licable to any style of boiler-furnace, Iwill dpescribe the present invention with respect to a returnflue boilerof the usual type, such a boiler being indicated at l in the drawingsand being mounted in suitable side or end walls in the usual manner. The'lire-box 2, however, is

carried well forward of the end of the boiler,

so that a large portion of the arched cover or roofing of the 'lire-boxextends in front of the front end of the boiler, and the grate 3 occu-The present invention involves the peculiar construction of the furnace,whereby air may be delivered through the arched top of the 'fire-box, aswell as through the speciallyconstruc'ted bridge-wall at the rear end ofthe fire-box.

iAs seen best in Fig. 1, the greater portion of the fire-box 2, whichprojects beyond the end of the boiler 1, is formed with a cover or topportion made up of two arches-an inner arch 4 and an upper or outer arch5. A space 6 is left between these arches, which extends over almost theentire space between the two arches. The front portion of the arch IOO 5is formed with any suitable apertures 7, y

The space between the arches 4 and 5, at the rear edges thereof, ispartially closed by a series of blocks or bricks 8, arranged to havesuitable spaces 9 therebetween.

The structure by which theair delivered through the bridge-wall isproperly heated also forms an important feature of the presentinvention. The bridge-wall 11 is extended rearwardly in the furnace fromthe fire-box to a considerable extent, making the said bridge-wallcomparatively thick, and interiorly of the bridge-wall is formed anairchamber 12. The upper surface of the bridgewall is inclinedrearwardly and upwardly, so that the rear upper edge of lthe bridge-wallapproximates the lower surface of the boiler 1 more than any otherportion of said bridgewall. The volume of iiame and burning gases andother products pass from the 'lirebox 2 upwardly over the inclinedsurface of the bridge-wall and against the under surface of the boiler,when it is more or less deflected and passes over the rear edge of thebridgewall and downwardly into the flame-chamber 13. The volume of flamein this chamber strikes the flame-bed 14, which forms the iloor of saidchamber, and then rises again at the rear end of the said chamber 18, soas to pass through the fiues in the boiler. The name-bed 14 is thus in aposition to become highly heated under the action of the flames andburning products, and in order to intercept the heat units and make useof them as they tend to pass downwardly through the flame-bed I form anumber of air-passages 15, which extend longitudinally through the ilower portion of the said flame-bed. These passages are preferablyformed by arranging parallel vertical walls or partitions 16 in the saidflame-bed, setting them a sufficient distance apart to make the passages15 of a proper width to accommodate an ample flow of air beneath theflame-bed. The walls 16, in addition to forming the passages 15, act asconductors for the heat received. from the upper portion of theflame-bed 14 and carry it well downwardly upon each side of each columnof air which passes through the passages 15. The columns ofv air thusbecome thoroughly heated. The passages 15 extend to the rear face of thebridge-wall 11 and communicate with the chamber 12, formed therein,through a series of small passages 17. These passages 17 are usuallymade of the same width as the passages 15, but are of much less depthand are preferably arranged in alinement with the upper edges ofpassages 15, as clearly shown in Fig. 1 of the drawings.

The rear ends of the passages 15 communicate with atransversely-arranged air-distributing chamber 18, which is mounted inthe rear portion of the furnace-brickwork, and air is supplied to thischamber through an inletpipe 19, which extends rearwardly therefrom andprojects beyond the rear face of the rear furnace-wall. The rear endsofpassages 15 are reduced in size by partially filling the same withbrickwork, as at 16a. This filling is ar ranged at the bottom of thepassages 15, so as to leave air-inlet openings 1 6b at the upper ends ofthe passages 15. Air will thus pass from the chamber 18 through thepassages 16bv into the passages 15. The forming of the passages 15 ofthe depth described and shown is advantageous for two reasons-namely,first, that it makes it possible to bring a large quantity of air incontact with a considerable amount of heated surface, and, second, thepassages 15 are deep enough to accommo date any collection of dust orforeign material which may be forced in with the air without any dangerof clogging or closing the passages. The pipe 19 preferably enters thewall at a point above the chamber 18 and is bent downwardly, so as toenter the said airchamber 18 from the top, as shown in Figs. 1 and 2. Anatural draft maybe permitted to carry air through said pipe into thechamber 18 and thence through the passages 15 to the bridge-wall; but Iusually prefer to em* ploy a fan, steam, or other blower for forcing airthrough said pipe and the passages above described. One end of theair-chamber 18 is capable of being opened and is 'normally closed bymeans of a door 20. Any accumulation of dirt or dust within the chamber18 may be removed by opening said door. A cleaning-floor is alsoprovided for the air chamber 12 in the bridge-wall 11, the said doorbeing indicated at 21. n

The chamber 12 is formed with a series of outlet-passages 22, which leadtherefrom in an inclined direction through the upper portion of thebridge-wall and deliver the air in its heated condition into the streamor column of flame and burning products which pass over the upper edgeof the bridge-wall. The outlets of the passages 22 are preferablylocated a short distance below the upper rear edge of the bridge-wall11, as clearly indicated in Fig. 1. These outlets may have down-'wardlyebeveled surfaces at 23 for preventing the lodging of dirt, soot,or products of combustion which may be carried through the flame-flueand over the bridge-wall. Although the brick portion of the upperportion of the bridge-wall may be made by various kinds of brick orother similar material, I find it preferable to form special bricks forfacilitating the construction of the air-pas- 'sages 22.

In Fig. 3 I have illustrated a preferable form of brick for supportingthe upper portion or edge of the bridge-wall 11. These bricks areconstructed with a triangular body portion 55. The upper inclined edgeof the body portion is formed with a series of stepped edges orshoulders, as at 56, the stepped portions being theheight of a brick,

ICO

so that the front bricks of the wall 11 can be fitted upon the same, asshown in Fig. 1. The stepped portions 56 are only arranged upon eachside of the upper inclined edge of said special brick, so that a grooveor inclined channel 57 extends between the said stepped` portions. Theunder edges ofthe opposite bricks are beveled, as at 58, to contributeto the formation of a smooth channel above each of the special bricksjust de# ldent that by vthis construction air may be taken in at therear of the furnace and passed through the passages 15, which are formedin the base or fla1ne-bed, the said air thus being allowed to intercepta large portion of the heat units which would otherwise merely passthrough the flame-bed, after which the air isv delivered into thebridge-wall and inl passing upwardly through the same becomes furtherheated, so that it is delivered into the :flames and burning productswithin the furnace in a highly-heated condition, and thus in readinessto combine with the liberated particles of carbon which have not beenconsumed through the action of the oxygen present in the fire-box. Thedirection of the passages 22 is such'that the streams of heated airforced through the bridge-wall will strike the volume of iiame whichpasses over the bridge-wall almost at right angles thereto, and althoughthe said streams of air will then 'be considerably deiiected they willbe thoroughly infused and mingled in the mass of flame and burningproducts which pass over the bridge-wall.

Any ordinary type of controlling mechanism may be provided for governingthe admission of air through the aperture 7, and I have illustrated aplate 32, mounted upon the arched cover or top of the fire-box andformed with a series of apertures spaced to coincide with and fit uponthe aperture 7. Slidingly mounted upon the plate 32 is a slide 33, whichis also provided with apertures corresponding to those of plate 32, thesaid slide being adapted to be moved for having its apertures coincidewith the apertures of plate 32. If it is desired to cut off a portion ofthe flow of air, it is only necessary to move the slide 33longitudinally to a greater or less extent for reducing the size of theinlet-openings. Any suitable means may be employed for controlling theaction of the slide 33, and I have illustrated in the drawings a simpleand preferable mechanism for this purpose comprising a rock-shaft 34,kmounted in a bracket 35 and provided at its rear end with a crank-arm36, which is connected by the link 37 with slide 33. The outer or frontend of the shaft 34 is also provided with a crank-arm 38, whichoverhangs the front of the furnace. A depending rod, as at 39, maybesecured to the free end of the crank-arm 38, and the voperator of thefurnace can easily grasp and pull down or push up said rod '39 forchanging the position of the slide 33.

While it is evident that., a natural draft may be employed at the rearof the furnace for supplying air to the bridge-walls and passages in thename-bed, it is preferable to use a forcing means at this point. When,however, a natural draft is sufficient, it is only necessary to leavethe rear end of the pipe 19 open, and the natural suction produced bythe movement of the flames and products of combustion beneath the boilerwill of course draw the air through the said passages and bridge-wall.

For supplying forced draft to the bridgewall I preferably employ asteam-jet 40, which is located opposite the open end of the pipe 19 andconnected with piping 41, which communicates with any suitable source ofsteam-supply. When a blower of this kind is employed, it is preferablysupplied with superheated steam from a coil of pipe 43, disposedintermediate the length ofthe pipe 41 and arranged in a recess 42,formed in the rear wall of the furnace adjacent to the fire-brick lining44. A valve 45 is preferably located in pipe 41 adjacent t-o the blowerfor controlling the passage of steam thereto. The valve is preferablyprovided with an operating-lever 50, which is pivoted adjacent to thevalve and is normally maintained in a lowered inoperative position by aweight 51. A chain 52 is connected with the lever 50 and is passed overthe furnace tothe front, suit-- able pulleys being provided forsupporting th'e chain for obviating friction. A suitable adjustablescrew 53 is arranged at the front of the furnace and engages the frontend of the chain 52 in such manner that the setting of the screw willoperate to lift the lever 50 or permit the same to drop, according tothe direction of the operation of the screw.

An aperture or apertures 49 may be formed in the arch 5 for permittingaccess to the space 6 for facilitating the removal of foreignsubstances.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. A furnace structure, comprising inclosing walls arranged to form afire-box and a flame-chamber, a hollow bridge-wall arranged between thefire-box and the iiamechamber, means being provided for affording ICOcommunication between the interior of the bridge-wall and thename-chamber, air heating and conducting passages being formed in theHoor of the flame-chamber, each of said passages being reduced in sizeat its ends and enlarged at its intermediate portion, each of the saidpassages communicating with the interior of the bridge-wall at one end,and means for delivering air to the other end of each of said passages.

2. A furnace structure, comprising inclosing walls arranged to form aiire-boX and 'a flame-chamber, a hollow bridge-wall disposed betweensaid 'lire-box and {lame-chamber, the bridge-wall being formed withmeans of' communication between its interior and the furnace-inclosure,air heating and conducting L passages communicating with the interior ofthe bridge-wall, each of said passages being formed small at each endand enlarged intermediate its length, a distributing-chamber disposedtransversely of the name-chamber and communicating with the ends of theair heating and conducting passages farthest distant from thebridgewall, and means for supplying air to said distributing-chamber.

3. In' an air-feeding mechanism for furnaces, the combination with afurnace-inclosure, of a hollow bridge-wall arranged therein and dividingthe saine into a fire-box and a name-chamber, a iame-bed arranged insaid chamber and formed with a plurality of longitudinally-arrangedparallel passages, a transversely-arranged air-chamber communicatingwith said passages, each of the passages being relatively small at thepoint of communication with the air-'chamber and relatively large beyondthe air-chamber, means for supplying air under pressure to theair-chamber, means of communication between said passages and theinterior of said bridge-wall, and means for delivering air from thebridge-wall to the furnace-inclosure.

4. In an air-feeding mechanism for furnaces, the combination with afurnace-inclosure, a hollow bridge-wall arranged therein, of air-heatingpassages formed in the floor of the fnrnace-inclcsure and communicatingwith the interior of the bridge-wall, a supply-chamber arrangedtransversely of and communicating with the endsof said passages farthestfrom the bridge-wall, the bridge-wall being provided with means of'communication between the interior of the bridge-wall and thefurnace-inclosure, and

an air-supply pipe extending from outsidecomplete the air-passages alongsaid grooves,

and means for delivering heated air through the said grooves into theflame-chamber of the furnace.

6. A furnace structure, comprising inclosing walls and a bridge-wallformed therein, said bridge-'wall being made hollow, ap-

proximately triangular bricks or blocks arranged across the upper edgeof the bridgewall each of said blocks having a plurality of steppedshoulderedportions leaving a space between them and top bricks fittingupon said shouldered portions and completing passages in connection withthe spaces of the triangular blocks or bricks and means for deliveringair in a heated condition through the said passages.

In testimony whereof I a'HiX my signature in presence of two witnesses.

VILLIAM MCCLAVE. Witnesses:

CAssELL SEvERANcE, JOHN L. FLETCHER.

